1. Field of the Invention
The present invention relates generally to methods of addressing data packets destined to a host in a communications network, and particularly to a method of defining an address for a mobile terminal/host while it is linked with the network via network base station cells.
2. Discussion of the Known Art
A known method of routing messages to wireless mobile terminal/hosts (T/Hs) that access the Internet via network base station cells, involves assigning only one unique Internet Protocol (IP) address for each mobile T/H. All traffic destined to a mobile T/H is thus addressed and transmitted to one site address for the mobile T/H. A home agent or "proxy" is located at the site of the IP address, and forwards the traffic to the mobile T/H. The latter continuously informs the site address of its present location. Thus, a messaging protocol is needed between the mobile T/H and the proxy at the T/H's fixed IP site address, to ensure that the proxy always has an updated forwarding address for the mobile T/H.
There are two problems with the known forwarding method. First, the mentioned mobile IP messaging must be incorporated into the Internet. Hence, all routers with which the mobile T/H connects must be able to support such mobility management. Second, traffic destined to the mobile T/H is always transmitted to the site of the T/H's fixed IP address, regardless of the actual location of the mobile T/H at any moment. This results in wasted bandwidth and additional delay that may be unacceptable when, for example, transmitting real-time data such as audio, video, simulation data or the like. See also U.S. Pat. No. 5,652,751 (Jul. 29, 1997) which relates to message routing schemes for wireless mobile networks having dynamically changing topologies.